Motor-fuel.



E. W.,STEVENS. MOTOR FUEL. APPLICATION FI LED NOV-21,1911- 1,259 %3e Patented. Mar. 12, 1918.

/ HOU RS c c VOLUME 60F.

GRAVITY BEAUME @uwntoi ethyl ELBRIDGE W. STEVENS, 0

F BALTIMORE, MARYLAND.

MOTOR-FUEL.

Specification of Letters Patent.

Patented Mar, 12, T918,

Application filed November 21, 1917. Serial No. 203,191.

To all whom it may concern:

Be it known that T, ELBRIDGE WEBSTER STEVENS, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Motor-Fuels, of which the following is a specification.

This invention relates to motor fuels; and it comprises a motor fuel containing in admixture ordinary kerosene or other burning oil, such as the commercial product known as export oil, ether, ethyl alcohol, a little fusel oil and some toluol; an advantageous proportioning of these bodies being about 5055 parts of kerosene or export oil, 30

arts of ordinary grain alcohol, about 5 parts of fusel oil (which may be contained in the alcohol used if this be an unrectified alcohol), about 10 parts of ordinary ether or what is known as sulfuric ether) and about 8 parts of toluol (sometimes known as toluene) all as more fully hereinafter set forth and as claimed.

In the operation of an ordinary internal combustion engine with gasolene, the reactions or operations which take place in the explosion in the cylinder of the engine are not in any way known; but the net result is of course combustion of the gasolene; this combustion furnishing heat and gases to produce the explosion. Probably the actions depend to a large extent on the particular type of carbureter used, the way in which the mixture is made, the compression, etc. But in practice it is difficult to obtain perfect combustion; that is, a combustion without the production of unburned bodies in the nature of tar, soot and carbon. The gasolene which is used in these engines is not anything of a definite nature; the most of the gasolene obtained on the market today is not the same thing as that which was sold as gasolene some years ago; but in a general wa gasolene may be described as a mixture of low boiling and light petroleum hydrocarbons with as much heavier, high boiling hydrocarbons as can be used and still obtain a reasonably good combustion in the engine. But with most commercial grades, this combustion is, as stated, not very perfect; most engines are apt to deposit carbon in the cylinders and smoke with most commercial grades of gasolene. The price of kerosene or burning oil being much lower than the gasolene, the temptation to the manufacturer is of course to put as much of the lower boiling kerosene oils into the gasolene oils as possible. Very many propositions have been made for producing mixtures of combustible liquids as substitutes for gasolene and some of these have gone into use. There are of course many other volatile and combustible liquids which may be used in the engine cylinder. But with most of these substitutes for gasolene there is either the difficulty of a weak explosion, that is, not enough power, or of a smoky combustion, as with much of the gasolene sold today for motor car use. Alcohol, for example, gives a clean and perfect combustion in the engine cylinder but not a strong explosion; it is not rich enough in hydrogen and carbon to develop much power.

In the present invention T have devised a motor fuel free of the noted objections; a liquid fuel which in the engine cylinder will give both a strong and powerful explosion and a clean combustion; a complete combustion without the smoke which indicated the production of tar, soot or coke. To this end I utilize, as does the modern gasolene manufacturer for that matter, kerosene as a base, as a material for furnishing the carbon and hydrogen whose combustion Wlll give the power. But, unlike the manufacturer of gasolene, instead of depending on light petroleum oils to give the necessary volatility and necessary inflammability, l substitute a mixture of other volatile combustible bodies of known properties. Obviously, by taking such a definite thing as ethyl alcohol and another such definite thing as toluol, ll can,

by uslng the two in suitable proportions, give any desired degree of volatility or flash point to the mixture without finding it necessary to take the flash point or constitution of thekerosene itself into consideration. T find however that to accomplish the best results with ordinary kerosene or burning oils, a rather definite and special composition containing, not only toluol and alcohol, but also ordinary ether (usually known as sulfuric ether) and a little fusel oil should be used. Unrectified grain alcohol of commerce often contains enough fusel oil for the present purposes but where it does not, T add the necessary amount. The best results I find T can obtain with a composition containing a little over 50 per cent. of ordinary kerosene or export oil, about 25 per cent. of ethyl alcohol or grain alcohol,'about 5 per cent.

lllltl ture because of the of fusel oil, about 10 per cent. of ether and about 8 per cent. of toluol. These pro portions are, in a way, rather necessary. I find, for example, that by taking very much less or very much more of toluol than about 8 per cent. of the final composition, the fuel will smoke in the en gine. I can go, as regards toluol, as low as perhaps 4 per cent. or I can go as high perhaps as 12 per cent. withoutsmoke; but about 8 per cent. is best. With the proportions stated the fuel develops ample power in the cylinder and does not smoke. I therefore recommend these proportions, or substantially the same proportions, as the best. I find that the statement about non-development of smoke with these proportions is true of all the ordinary automobile engines equipped with the ordinary types of carureters.

As to the reason why this particular composition gives these results, I cannot say definitely; the fact has been worked out as result of experience. It is probable however that, at least with some engines, this mixproportions of these volatile liquids, on entering the hot engine cylinder, disrupts, so to speak, explosively, by flashing of the volatile liquids into vapor with production of very finely subdivided kerosene which, by reason of its enormous surface, burns within the infinitesimal time afforded in the engine. Possibly, with some earbureters and some engines the perfect combustion is due to some other factors. I content myself with noting the fact without committing myself to any theory of the action.

As the ethyl alcohol or grain alcohol component of the mixture I may take any commercial grade of strong alcohol. The stronger it is, however, the better. Any undue amount of Water in the alcohol not only interferes with mixture and perfect solution, using the quantities of materials mentioned but also reduces the force of the explosion in the cylinder. It may or may not have been rectified. In event it has been'rectified and freed of fusel oil, I add some fusel oil (amylalcohol), as .stated. In case it is necessary to add fusel oil or amylalcohol, I may use any of the commercial grades. I find it is necessary, to obtain the best results, to use between 2 and 5 per cent. of fusel oil in the finished composition. The fusel oil seems to have, to a large extent, in this composition the function of maintaining the blend. With this fuel, as With any other composite fuel, including ordinary gasolene, there is of course a tendency for the more volatile portions to evaporate, leaving the less volatile portions behind, or, in other words, the liquid changes in character. The fusel oil appears to operate to prevent this change on exposure to air; not only by reposition is very tarding the evaporation of the more volatile components, that is, of the alcohol and ether,

any change in its proportion by exposure to the air gives a very different action in the engine. I find that where the toluol is omitted or it is not present between the limits stated, the ether component of the comapt to be lost in time. It is probably for this reason that the lower limit of 4 per cent. toluol is necessary. Too much toluol, that is, more than about 12 percent. of the finished composition in and of itself will make the composition smoky. As the kerosene component of the fuel I may use any of the commercial grades; and I may indeed use even heavier grades of petroleum distillates than those which are sold as burning oil, such as, for example, the lighter fractions of gas oil or solar oil. Cracked kerosenes are as useful as the heavily treated saturated refinery kerosenes. One commercial grade of kerosene of cracked character which is so low in quality that it is generally sold abroad and is therefore called export oil may be very well used in the presentinvention. As stated, in the present invention I am relying upon the kerosenes for power only; the other components of my mixture giving the character which is necessary to render the kerosene quickly combustible in the cylinder. Therefore, within limits, I can use any commercial hydrocarbon oil as a substitute for kerosene; even tar oils, such as are recovered from coal tar, Wood tar, water gas tar, etc. But a good grade of commercialkerosene is a satisfactory component of my mixture.

I find a good grade of commercial toluolthe best for my purposes but I can use other aromatic oils from coal tar with more or less satisfaction, such as Whatis known as crude benzola liquid which is only in part benzol and contains toluol and xylol. The heavy oils recovered in distilling coal tar and containing xylols may be used for my purposes. They also have an etherretaining quite as large a per cent. as toluol. a heavy tar oil as 4 or 5 per cent., smokiness.

With a rule I do not go above since more would produce Of course I am here speaking of power; but they cannot be used in 1 a fuel which contains somewhere about half maaoaa its weight of kerosene. If the amount of kerosene be reduced, more of these heavy tar oils may be used without producing smokiness. The same is of course true of toluol or crude benzol.

A motor fuel of the type here described remains perfectly blended and of uniform character even after long periods of exposure to the open air and rough handling. It is more stable on exposure to the air than commercial gasolene, that is, it changes less in character. In the engine cylinder, I find as a rule that I can produce more power with a gallon of the present material than with the average gasolene now on the market. There are special gasolenes which will develop more power, but gasolene as it runs does not produce as much; and in some cases the margin in favor of the present fuel is very great.

For a fuel for aeroplane work, where extreme conditions of cold in high altitudes affect the carbureter action and where there is present a liability of the engine to overheat because of the high load factor, I find it useful to reduce somewhat the proportion of kerosene in my mixture. For such purposes, I have found a fuel composed of about per cent. of kerosene, about 31 per cent. of ethyl alcohol, about 4 per cent. of fusel oil, about 15 per cent. of ether and about 10 per cent. of toluol, 'very useful. In lieu of ordinary ether, (C H 0, in some cases the very volatlle fractions of petroleum known on the market as petroleum ether may be employed, or even the still more volatile materials known as casinghead gasolene 'eathered or unweathered) may be substituted; but I regard the ordinary ether as more advantageous. For one thing, ether, like alcohol, seems to fire quicker in the cylinder than do substances not containing any oxygen like petroleum ether, even where the volatility is the same.

In the described composition, the ether is" of course the most volatile constituent and the one which is easiest lost by evaporation. The influence of the toluol and also of the fusel oil (to a less extent) is to restrain this evaporation. And as a matter of fact, in the present invention, the evaporation is very little. The ether and alcohol in the present invention give the volatility which is required in the engine cylinder while the volatility at ordinary temperatures is controlled by the other ingredients present. The volatility at ordinary temperatures may be controlled by varying'the proportions of toluol. In the accompanying curve sheet I changes have illustrated the phenomena. InFig. II have shown in the form of curves the loss by evaporation in a very stable and permanent commercial gasolene (curve A). Curve B represents the loss with a fuel containing as high as 15 per cent. of ether; that is, of such a mixture as I use for aeroplane work. Curve 0' represents a fuel containing still more ether, 20 per cent. It will be noted that even with these high percentages of ether in the mixture the loss is not much more than that of ihe gasolene. The figure shows the proportions of liquids remaining when 100 cc. were taken and exposed to free contact with the air for the time noted on the table. It will be noted that in 80 hours, with the highest proportion of ether, there is still a loss of only about 12.5 cc. out of 100 cc. or 12.5 per cent, while in the same period of time the gasolene loss was 8 cc. In the work' on which these curves were based, theliquids were exposed to air in open test tubes, the exposed surface being the same for. all three. In Fig. 2, I have shown graphically the same phenomena in another way; the curves here express the relative drop in Baum gravity (which really means an increase in specific gravity) on exposure to air. In this figure curve A represents the in ordinary gasolene. Curve shows the action in a fuel containing about 50 per cent. export oil of 110 flash, 30 per cent.- of ethyl alcohol and 4 per cent. fusel oil, 8 per cent. ether and 8 per cent. toluol. It may be noted with regard to the gasolene whose properties are diagrammed in curve A that this particular gasolene would make very difiicult motor starting in cold weather. Present grades of commercial gasolene are too low in volatility to give the easy motor starting required in cold weather or the flexmy new ether to the ether-retaining toluol (and fusel oil) such as to give the desired qualities of easy starting, etc., and at the same time retain the quality of stability in the fuel.

What I claim is 1-. As a newmotor fuel, a mixture containing a heavy petroleum oil, to furnish power, with admixed ethyl alcohol, fusel oil, ether and toluol.

2. As a new motor fuel, a liquid material composed of about 52 parts kerosene, about 25 partsethyl alcohol, about 5 parts fusel oil, about 10 parts ether and about 8 parts toluol.

In testimony whereof, I aflix my signature 

